The present disclosure herein relates to a photodetector, and more particularly, to a photodetector using an avalanche effect.
A germanium-on-silicon photodetector is an optical device developed in order to amplify a small optical signal to have high efficiency and is generally fabricated by the epitaxial growth of a deposition layer, a charge layer, a germanium optical absorption layer, and a contact layer on a silicon substrate. Since in such an epitaxial growth process of many layers, it takes a long time and the quality of an epitaxial growth layer affects the performance of a device, a yield decreases in a fabrication process.